29 documents found, page 1 of 3
Facultative anaerobic bacteria enable syntrophic fatty acids degradation under ...
Magalhães, Carla Isabel Pereira; Duarte, Maria Salomé; Pereira, M. A.; Stams, Alfons Johannes Maria; Cavaleiro, Ana JúliaTrace amounts of oxygen stimulate facultative anaerobic bacteria (FAB) within anaerobic bioreactors, which was shown to correlate with enhanced methane production from long-chain fatty acids. The relationship between FAB and fatty acid-degrading syntrophic communities under micro-aerobic conditions is still not clear. In this work, two syntrophic co-cultures, Syntrophomonas wolfei+Methanospirillum hungatei and ...
Metabolic versatility of anaerobic sludge towards platform chemical production ...
Magalhães, C. P.; Alves, Joana I.; Duber, Anna; Oleskowicz-Popiel, Piotr; Stams, Alfons Johannes Maria; Cavaleiro, Ana JúliaWaste glycerol is produced in excess by several industries, such as during biodiesel production. In this work, the metabolic versatility of anaerobic sludge was explored towards waste glycerol valorization. By applying different environmental (methanogenic and sulfate-reducing) conditions, three distinct microbial cultures were obtained from the same inoculum (anaerobic granular sludge), with high microbial spe...
Pseudomonas empower syntrophic fatty acids degradation in the presence of oxygen
Magalhães, Carla Isabel Pereira; Duarte, Maria Salomé; Pereira, M. A.; Stams, Alfons Johannes Maria; Cavaleiro, Ana Júlia; Alves, M. M.Anaerobic digestion (AD) processes specifically directed towards biogas production are currently of great interest worldwide, due to the urgent need of more sustainable energy sources. Although not consensual, oxygen has been shown as an ally of AD processes, resulting in more efficient biogas production when added to the systems in vestigial doses. It has been suggested that it stimulates facultative anaerobic...
The protective effect of Pseudomonas in syntrophic fatty acids degradation unde...
Magalhães, C. P.; Duarte, Maria Salomé; Pereira, M. Alcina; Stams, Alfons Johannes Maria; Cavaleiro, Ana Júlia; Alves, M. M.Micro-aeration has been used in anaerobic digestion (AD) systems to improve some aspects of this multifunctional and flexible technology. The addition of vestigial amounts of oxygen is usually associated with an increase of the relative abundance of facultative anaerobic bacteria (FAB) in the microbial community. Besides being involved in fermentation/acidogenesis, FAB have been referred to act as a protective ...
Corksorb enhances alkane degradation by hydrocarbonoclastic bacteria
Martins, Valdo R.; Freitas, C.; Castro, Rita; Silva, Ana Rita Marques; Gudiña, Eduardo José; Sequeira, J. C.; Salvador, Andreia Filipa FerreiraBiosorbent materials are effective in the removal of spilled oil from water, but their effect on hydrocarbonoclastic bacteria is not known. Here, we show that corksorb, a cork-based biosorbent, enhances growth and alkane degradation by Rhodococcus opacus B4 (Ro) and Alcanivorax borkumensis SK2 (Ab). Ro and Ab degraded 96 ± 1% and 72 ± 2%, respectively, of a mixture of n-alkanes (2 g L1) in the presence of corks...
Multi-walled carbon nanotubes enhance methanogenesis from diverse organic compo...
Cavaleiro, Ana Júlia; Salvador, Andreia Filipa Ferreira; Martins, Gilberto; Oliveira, C. P.; Liu, Y.; Martins, V. A.; Castro, RitaConductive nanomaterials affect anaerobic digestion (AD) processes usually by improving methane production. Nevertheless, their effect on anaerobic communities, and particularly on specific trophic groups such as syntrophic bacteria or methanogens, is not extensively reported. In this work, we evaluate the effect of multi-walled carbon nanotubes (MWCNT) on the activity of two different anaerobic microbial commu...
Long-chain fatty acids degradation by desulfomonile species and proposal of can...
Alves, J. I.; Salvador, Andreia Filipa Ferreira; Carvalho, Ana Rita Castro; Zheng, Ying; Nijsse, Bart; Atashgahi, Siavash; Sousa, Diana Zita MachadoMicrobial communities with the ability to convert long-chain fatty acids (LCFA) coupled to sulfate reduction can be important in the removal of these compounds from wastewater. In this work, an enrichment culture, able to oxidize the long-chain fatty acid palmitate (C16:0) coupled to sulfate reduction, was obtained from anaerobic granular sludge. Microscopic analysis of this culture, designated HP culture, reve...
Co-cultivation of Thermoanaerobacter strains with a methanogenic partner enhanc...
Magalhães, Carla Isabel Pereira; Ribeiro, Joaquim Alfredo França Martins; Guedes, Ana P.; Arantes, Ana Luísa; Sousa, Diana Zita MachadoGlycerolrich waste streams produced by the biodiesel, bioethanol and oleochemical industries can be treated and valorized by anaerobic microbial communities to produce methane. As current knowledge of the microorganisms involved in thermophilic glycerol conversion to methane is scarce, thermophilic glyceroldegrading methanogenic communities were enriched. A coculture of Thermoanaerobacter and Methanothermobacte...
Effect of sub-stoichiometric Fe(III) amounts on LCFA degradation by methanogeni...
Cavaleiro, Ana Júlia; Guedes, Ana P.; Silva, Sérgio Alves; Arantes, Ana Luísa; Costa, João Carlos Sequeira; Salvador, Andreia Filipa FerreiraLong-chain fatty acids (LCFA) are common contaminants in municipal and industrial wastewater that can be converted anaerobically to methane. A low hydrogen partial pressure is required for LCFA degradation by anaerobic bacteria, requiring the establishment of syntrophic relationships with hydrogenotrophic methanogens. However, high LCFA loads can inhibit methanogens, hindering biodegradation. Because it has bee...
Aerobic and facultative bacteria: working horses at the service of anaerobic di...
Duarte, Maria Salomé Lira; Oliveira, João Vítor; Magalhães, Carla Isabel Pereira; Salvador, Andreia Filipa Ferreira; Carvalho, Ana Rita CastroIt is clear that aerobic and facultative anaerobic bacteria have an important role in the first steps of the anaerobic digestion (AD) process, especially when complex organic compounds are degraded. However, their diversity, abundance and function, related to the fine control of process variables such as pH and ORP, and the potential establishment of networks with methanogens and acetogens are far from being fu...